1990 70HP Rude Power Trim Servicing

[degull]

Hello everyone. I recently purchased a 1990 70HP Evinrude with power trim/tilt and I would like to know how to service the power trim module with hydraulic fluid. I have not had a chance to get a manual for it yet but I figured with all the experts around this is a no brainer. Early November morning I was staring out to winterize the motor when I realized the tilt/trim was not working. Checked out the voltage to the trim motor and it seemed correct with +/- 12 volts. It was cold that morning with frost on the ground. Decided to work around it and after a couple of hours when it warmed up outside the trim/tilt started to work again.

Since I was winterizing it, I decided to pull the power trim module and take it home to play with it over the winter. The boat is being stored a couple of hours from my home.

I took the electric trim motor apart and found the commutator full of crud. I cleaned it up real nice so the copper shined again and put it back together. It's working well and I suspect the dirty comm was the reason it did not work on that cold November morning.

With the electric trim motor removed from the module I noticed that the hydraulic fluid was black instead of clear red like tranny fluid. I would like to service the unit with new fluid but not really sure how to drain/fill/bleed the unit. I've attatched three pictures of the module below. The plugs are numbered because I'm not sure what any of them are for.

Any help would be appreciated. Thanks!

http://www.flickr.com/photos/11319197@N06/2146802451/

http://www.flickr.com/photos/11319197@N06/2147596652/

http://www.flickr.com/photos/11319197@N06/2146803011/

 

[Gary H NC]

Re: 1990 70HP Rude Power Trim Servicing

If its working fine now i would remove the #1 screw,thats the fill plug.Its off the boat so drain what you can by cycling up and down with the plug out.Refill and do it again.#2 i believe is the manual release and #3 is the reverse lock valve.I would not mess with them if i did not need to.I would have to look in my shop manual to say what the other plugs are.Its been awhile.
The factory service manual would big a big help to you..

 

[degull]

Re: 1990 70HP Rude Power Trim Servicing

So I can run the motor up and down with no fluid in it? If I drain it out the fill port by running it up and down how will all the fluid get out? Should I turn it upside down while running the motor to help the fluid come out? I'd like to flush the system by adding fresh fluid then dump it again. The fluid in there was probably original so it was pretty dirty.

I'll get a manual eventually, but thought I'd get someone on here has done hundred's of these.

I really appreciate your help. Thanks.

 

[HighTrim]

Re: 1990 70HP Rude Power Trim Servicing

You will be able to get most of the oil out of the fill hole (#1) as Gary said, but you may need to remove one of the SS oil lines, and manually activate the cylinder to remove it all. You can fill most of it, but may need to wait until re installed on the outboard to be able to cycle it enough times to bleed the air. The system is self bleeding, meaning it will bleed itself by cycling the trim motor up and down. Fill it with the motor trimmed all the way up, cycle it a few times, re fill, cycle it, etc... until you cannot add any more. I like using the BRP TNT fluid, but other use ATF Dexron

 

[degull]

Re: 1990 70HP Rude Power Trim Servicing

That sounds pretty simple. I'll pull off the lowest point on both of the oil lines to try to get the dirty oil out.

Just so I'm clear, # 2 is to manually release the motor down and # 3 is to manually release the motor up correct?

Thanks so much guys.